THE NITROGEN OF PROCESSED FERTILIZERS. 21 
isolated from the base goods are actually available to plants as such 
and have a beneficial action. Of the monoamino acids, other than 
the two isolated from base goods, which have been studied in regard 
to their action on plant growth, three have been found to be beneficial, 
one doubtful, and one is reported as being harmful. 
The high-grade nitrogenous fertilizers, such as dried blood, are 
considered to have a high availability owing to the fact that the 
nitror^cnous materials when placed in the soil quickly undergo the 
process of ammonification and nitrification, the nitrogen thus being 
changed into a form which can be immediately used by the plant. 
In fact, Lipman ^ has proposed a method for the determination of the 
availability of the nitrogen of organic fertiUzers, depending on the 
amount of ammonia produced under certain conditions in a given 
length of time. It is evident from the above consideration that such 
a method does not tell the whole story, since in the decomposition of 
protein materials Uke dried blood intermediate compounds are 
formed which are undoubtedly in themselves beneficial to plant 
growth. In order, therefore, to understand the complete action of 
the nitrogenous materials in the base goods it is necessary to know 
how the compounds contained in it are acted upon by ammonifying 
bacteria. Jodidi ^ has shown that the amino acids, and acid amides 
are quite readily ammonified when placed in the soil, the rate of 
ammonia formation and the amount of ammonia formed depending 
apparently upon the chemical structure of the particular compound 
under consideration. In general, he found that the simpler the chem- 
ical structure of the nitrogen compoimd the more quickly and readily 
it was ammonified. In the light of these facts it appears that poly- 
pep tids, peptones, proteoses, and proteins would be ammonified still 
more slowly than the amino acids since their structure is increasingly 
more complex. 
Hartwell and Pember ^ in their study on the availability of the 
nitrogen of base goods, by means of plant tests found that it had 
apparently as high an availabihty as dried blood; the water soluble 
nitrogen having even a higher availabihty. From the nature and 
amounts of the compounds present in the base goods this might bo 
predicted. In the case of the dried blood, the nitrogen is practically 
all in the form of complex protein material which must be broken 
do^vn into simpler compounds by bacterial action, with the formation 
of ammonia and other nitrogenous compounds, some or all of which 
may be of physiological importance to plants. With the base goods 
the case is a little different, the greater part of the nitrogen is at 
once available for plant use, and at the same time these available 
compounds may be changed more easily and quickly by the bacteria 
1 B -1. 246, New Jersey Expt. Sta., 1912. 
2 Research B'll. No. 9, Iowa Expt. Sta. 
3 Loc. cit. 
